Refrigerating cycle apparatuses comprising rotary compressors are often used. In a rotary compressor of this type, an electric motor portion and a compression mechanism portion are joined through a rotation axis, and the compression mechanism portion is provided with a cylinder in which a cylinder chamber is formed, a roller moves eccentrically within the cylinder chamber, and a vane abutting the roller, the vane partitioning an inside of the cylinder chamber into a compression chamber and an intake chamber.
When the rotation axis rotates and the roller moves eccentrically within the cylinder chamber to compress a gas refrigerant that has been taken in, the pressurized gas refrigerant presses the roller and the rotation axis, and the rotation axis bends slightly. Then, the roller inclines and enters a so-called partial contact state in which a contact surface between the vane and the roller is uneven and they contact locally, a sliding resistance at a contact portion between the vane and the roller is increased, and friction progresses (for example, Japanese Patent No. 4488104).